Problems of controlled resistance occurred during my attempts to devise exercising equipment using a hard sphere set into a frame with a handle attached. Resolving controlled resistance problems seems to have been a major effort also in past art development. In a similar ball and handle exercising device, J.R. Anderson, U.S. Pat. No. 1,535,391, issued Apr. 28, 1925, tries to resolve the resistance problem with a ball in a tightenable socket. The J.G. Begley exercise device, U.S. Pat. No. 2,126,443, dated Aug. 9, 1938, also tightens a ball in a socket for resistance control. In U.S. Pat. No. 2,817,524, issued Dec. 24, 1957, to H.K. Sadler, the same problem is approached differently in that two soft washers tighten down on a disc to provide the controlled resistance. But in U.S. Pat. No. 3,428,311, dated Feb. 18, 1969, to T.J. Mitchell, we again see the ball in a tightenable receptacle. The C.H. Carson U.S. Pat. No. 4,344,615 describes a controlled friction exercising device using pressure applied to the cylindrical central portion of a bar.
In further developing my use of elastomeric spheres in the present invention, the state-of-the-art for other uses was viewed. In a power transmitting device shown by H.N. Coyell, U.S. Pat. No. 642,862, dated Feb. 6, 1900, friction drums encasing ball bearings is the clutching mechanism. A friction clutch is illustrated by G.M. Bennett in a patent issued Sep. 16, 1902, U.S. Pat. No. 709,194. In the E.J. Sweet U.S. Pat. No. 1,065,635, of Jun. 24, 1913, wedged rollers are used in his clutch. A frictional type ball gearing is disclosed in the W.E. Buffat device, U.S. Pat. No. 1,229,879, issued Jun. 12, 1917, and a friction transmission device is disclosed in U.S. Pat. No. 2,209,254, dated Jul. 23, 1940, issued to Y.A. Ahnger. A massage roller in which a pair of soft balls are frictionally engaged by handles is described in U.S. Pat. No. 2,286,324 issued to J.L. Wentz Jun. 16, 1942. U.S. Pat. No. 2,316,874, issued Apr. 20, 1943 describes a cone clutch devised by H.T. Kraft, and U.S. Pat. No. 2,344,592, dated Mar. 21, 1944, allowed to R.L. Brownless discloses a power take-off clutch.
A transmission is disclosed by P.S. Morgan in U.S. Pat. No. 2,682,776, dated Jul. 6, 1954, and a controlled torque coupling for converting rotary motion and using resiliently compressible tubular members is described by V. Dall'Olio in U.S. Pat. No. 2,848,883, issued Aug. 26, 1958. B.J. Griffin invented the exercising device with coiled springs described in U.S. Pat. No. 2,973,962, issued on Mar. 7, 1961, and J.C. Littman invented the momentary flexible, motor drive overload release device utilizing resilient rollers issued in U.S. Pat. No. 3,554,045 on Jan. 12, 1971. A torque limiting coupling utilizing resilient spherical members is described in U.S. Pat. No. 4,056,953, issued to J.L. Furlette on Nov. 8, 1977, and an exerciser and tension relieving device is described by G.P. Olsen in U.S. Pat. No. 4,208,047, issued Jun. 17, 1980. Finally, U.S. Pat. No. 4,401,208, issued Aug. 30, 1983 to D.S. Allmacher, Jr. describes an accumulating conveyor system utilizing torque limiting elastomeric rollers.
The foregoing, being the most pertinent devices disclosed in the prior art directly related to the present invention, do not disclose the use of elastomeric spheres for frictional control as advanced as the principle herein disclosed.